I think there's a seperate reason as to why, "everynow and then a simple webpage doesn't want to appear, after clicking 20 times, suddenly everything is OK".

There's probably just some network lag, or something.

No, if that was the case I would have detected it. No, doesn't anyone know something about PHP and XP and stable action? I hope so.

You got a scorching internet connection? If not then this is most likely the problem, standard broadband connections generally arent suitable for web servers, i know this because i tried my self, my 2Mb connection simply couldnt cut it. Also make sure your ISP allows servers or they may come down on you like a ton of bricks. Another thing, if you have unlimited bandwidth on a standard ISP, then a fair usage policy will be in place and you will risk dis-connection if you "abuse" the service.

If however you have a backbone connection (which is where a website should be) however then this obviously isnt the issue.
One thing, it is recomended that you install apache and php on a clean machine for obvious stability reasons.

Is this on your home box? If so, is it safe to assume you are accessing your web server locally or within your local home network (as opposed to having the site/server offsite)?

If that is the case, I would lean toward the stability of your setup (especially if you are serving web pages locally).

My suggestion, if it really took you 8 hours just to get it up and running the first time, is the following:

1.)Start with a fresh install

2.)Install WAMP - http://www.wampserver.com/en/index.php

That's probably the easiest way you are going to get one up and running*.

*Of course, if you really want stability (and this won't cost you a penny... ok maybe the cost of 1 - 4 burned CD's), just wipe that box and install Linux. Then, set it up as a LAMP server - http://www.lamphowto.com/lamp.htm